Just joined a new website called RunKeeper that enables people to track their running, walking and cycling etc. to help them get fit. What's great is that there is a mobile app (which is free!), that uses GPS to track your workout, which is great as it works out how many calories you have burned, your average speed, distance walked or run etc. and a Google map of where you went.
Have already completed 4 fitness events, using RunKeeper and I must say that it is a great help to me and motivates me to keep going, as every 5 minutes it gives me a rough estimate of how well I am doing.